| 摘要 |
PROBLEM TO BE SOLVED: To provide a biaxially oriented polyester film, which is excellent in dimensional stability and the strength of the edge of a tape, has an excellent running stability and running durability as the magnetic tape and is suitable for the base film of a high density magnetic recording tape. SOLUTION: This biaxially oriented polyester film includes a polyester and a polyimide as its essential components and has the circumferential half width A of a crystal face diffraction peak in the biaxially oriented polyester main chain direction obtained in the crystal orientational analysis in a wide angle X-ray diffraction, which is 30°or more to less than 55°, and the ratio ITD/IMD of the diffraction peak ITD in the width direction (90°) to the diffraction peak IMD in the longitudinal direction (0°) is set to be 0.2 to 2. COPYRIGHT: (C)2003,JPO |
